Impaired Gas Exchange

Impaired Gas Exchange

NANDA Definition

Impaired gas exchange is an excess or deficit in oxygenation and/or carbon dioxide elimination at the alveolar-capillary membrane.

Discussion of the Problem

Diffusion is the process by which oxygen and carbon dioxide are exchanged at the air-blood interface. The alveolar capillary membrane is ideal for diffusion because of its thinness and large surface area. In normal healthy adults, oxygen and carbon dioxide travel across the alveolar-capillary membrane without difficulty. Ventilation is the flow of gas in and out of the lungs, and perfusion is the filling of the pulmonary capillaries with blood. Adequate gas exchange depends on an adequate ventilation-perfusion (v/Q) ratio. In the healthy lung, a given amount of blood passes an alveolus and is matched with an equal amount of gas (A). The ratio is 1:1 (ventilation matches perfusion). Impaired gas exchange results when there is alteration in the balance between the ventilation and perfusion (V/Q) ratio. Medical conditions that could lead to impaired gas exchange are as follows: COPD, asthma, atelectasis, pulmonary edema, and adult respiratory distress syndrome (ARDS) heart failure, lung cancer, pneumonia, pulmonary tuberculosis (TB), respiratory acidosis, respiratory alkalosis, septicemia, sickle cell crisis, thrombophlebitis, deep vein thrombosis and AIDS. Other factors affecting gas exchange include high altitudes, hypoventilation, airway blockages, local changes in compliance, gravity, altered oxygen-carrying capacity of the blood from reduced hemoglobin, history of smoking or pulmonary problems, obesity, prolonged periods of immobility, and chest or upper abdominal incisions. In addition, pulmonary blood flow and diffusion decreased as a person ages. The overall managements for patients with oxygenation problems are to maintain a patent airway, improve comfort and ease of breathing, maintain or improve pulmonary ventilation and oxygenation, improve ability to participate in physical activities, and to prevent risks associated with oxygenation problems such as skin and tissue breakdown, syncope, acid-base imbalances, and feelings of hopelessness and social isolation.

Nursing Interventions Classification (NIC)

• Acid-Base Management: Respiratory Acidosis
• Acid-Base Management: Respiratory Alkalosis
• Airway Management
• Chest-tube care
• Embolus Care: Pulmonary
• Oxygen Therapy
• Respiratory Monitoring/Management

Nursing Outcomes Classification (NOC)

• Electrolyte and Acid-Base Balance
• Gas Exchange
• Knowledge: Disease Process
• Respiratory Status

Goal and Objectives

·         Patient wil Verbalize understanding of root factors and appropriate managements.

·         Patient will demonstrate enhabced ventilation and sufficient oxygenation of tissues by ABGs within patient’s usual range.

• Patient will maintain maximum gas exchange as manifested by normal arterial blood gases (ABGs) and alert responsive mentation or no further decrease in mental status.

·         Patient will participate in procedures to optimize oxygenation and in management regimen within level of capability/condition

·         Patient will verbalize/manifest resolution or absence of symptoms of respiratory distress.

Subjective and Objective Data

• Changes in ABGs/pulse oximetry
• Confusion

·         Cyanosis

·         Dyspnea

• Hypercapnia

·         Hypoxemia

• Hypoxia
• Inability to move secretions
• Irritability

·         Restlessness/changes in mentation

• Somnolence

·         Tachycardia

Related Factors

• Altered blood flow

·         Altered delivery of oxygen (hypoventilation)

• Altered oxygen supply (hypoventilation)
• Alveolar-capillary membrane changes (inflammatory effects)

·         Decreased oxygen-carrying capacity of blood/release at cellular level (fever, shifting oxyhemoglobin curve, blood loss)

·         Removal of lung tissue

Assessment (Dx)

• Auscultate lungs for air movement taking note areas of reduced ventilation and adventitious breath sounds. Consolidation and diminishing of air movement on operative side are usual in the pneumonectomy patient; yet, the lobectomy patient should manifest normal airflow in remaining lobes.

ABNORMAL BREATH SOUNDS
Bronchospasm	Continuous breath sounds of both rhonchi and wheezing; usually bronchodilator will help to alleviate this problem.
Expiratory grunt	A sign of distress, hypoxia, and/or increased work of breathing.
Rales	A fine crackle that can be heard during inspiration or expiration.
Rhonchi	Coarse crackle sound that is more wet than a rale, suctioning recommended.
Stridor	Usually caused by edema around the vocal cords or from an obstruction or tumor.
Wheeze ( whistling sound )	This is heard most commonly in asthmatics and CHF

·         Check body temperature, as necessary. Aids with comfort procedures to decrease fever and chills. Elevated temperature  greatly adds to metabolic demands and oxygen consumption and modifies cellular oxygenation

• Check for signs and symptoms of atelectasis, and they are as follows:  reduced chest excursion, restricted diaphragm excursion, bronchial or tubular breath sounds, rales, tracheal shift to affected side. Collapse of alveoli augments physiological shunting.

• Check for signs or symptoms of pulmonary infarction, and they are as follows: cough, hemoptysis, pleuritic pain, consolidation, pleural effusion, bronchial breathing, pleural friction rub, and fever.

• Check respirations: observe quality, rate, pattern, depth, and breathing effort. Both fast, shallow breathing patterns and hypoventilation influence gas exchange. Shallow or "sighless" breathing patterns post surgery (as a result of effect of anesthesia, pain, and immobility) decrease lung volume and reduce ventilation.

RATES AND DEPTHS OF RESPIRATION
Apnea	Period of cessation of breathing
Apneusis	sustained maximal inhalation with pause
Ataxic patterns	Irregular and unpredictable pattern with periods of apnea
Biot’s respiration	Periods of normal breathing (3-4 breathes) followed by a varying period of apnea usually 10-60 seconds).
Bradypnea	Slower than normal rate, <10 breathe/minute, with normal depth and regular rhythm
Cheyne-Stokes respiration	Regular cycle where the rate and depth of breathing increase, then decrease until apnea (usually about 20 seconds) occurs.
Eupnea	Normal, breathing at 12-18 breaths/minute
Hyperventilation	Increased rate and depth of breathing
Kussmaul’s respirations	Deep respirations with fast, normal, or slow rate
Tachypnea	Rapid, shallow breathing, > 24 breaths/minute

• Check results of position changes on oxygenation. Placing the most congested lung areas in the dependent position (where perfusion is greatest) fascilitates ventilation and perfusion imbalances.

• Check vital signs. With preliminary hypoxia and hypercapnia, blood pressure, heart rate, and respiratory rate all increased. As the hypoxia and/or hypercapnia turn out to be more severe, BP may fall, heart rate tends to continue to be fast with arrhythmias, and respiratory failure may develop with the patient unable to sustain the fast respiratory rate.

• Evaluate patient’s capability to cough efficiently to mobilize secretions. Observe amount, color, and consistency of sputum. Retained secretions reduce gas exchange.

·         Examine ABGs, pulse oximetry readings. Chech hemoglobin (Hb) levels. Diminishing Pao₂ or elevating Paco₂ may signify requirement for ventilatory support. Important blood loss can lead to reduced oxygen-carrying capacity, decreasing Pao₂.

ANALYZING A BLOOD GAS
1. Note the pH.  Determine if it is acidosis or alkalosis. 2. Note the PaCO2.  Is it normal, increased, or decreased? 3. Note the HCO3.  Is it normal, increased, or decreased? 4. Note the base excess or deficit. 5. Note the PaO2 to determine if there is hypoxia.
NORMAL BLOOD GAS VALUES
pH	7.35 - 7.45
PaCO2	35 - 45
PaO2	80 - 100  ( in infants normal PaO2:  60 - 80 )
HCO3	20 - 24

• Examine restlessness and alteration in mentation or level of consciousness (LOC). Restlessness is an initial manifestation of hypoxia. Chronic hypoxemia may lead to cognitive alterations such as memory changes. May signify augmented hypoxia or complications such as mediastinal shift in pneumonectomy patient when along with the following:  tachypnea, tachycardia, and tracheal deviation

·         Monitor color of skin, mucous membranes, and nailbeds, observing existence of peripheral cyanosis or central cyanosis. Cyanosis of nailbeds may signify vasoconstriction or the body’s reaction to fever or chills; on the other hand, cyanosis of earlobes, mucous membranes, and skin around the mouth is suggestive of systemic hypoxemia.

• Monitor for signs and symptoms of hypoxemia: tachycardia, restlessness, diaphoresis, headache, lethargy, and confusion.

·         Note incidence/degree of bubbling in water-seal chamber. Air leaks immediately postoperative are not unusual, particularly following lobectomy or segmental resection; yet, this should lessen as healing advances.Extended or new leaks meed assessment to recognize problems in patient versus the drainage system.

• Note skin color for progression of cyanosis. 5 g of hemoglobin must desaturate for cyanosis to occur.

·                   Observe alterations in quantity/type of chest tube drainage. Bloody drainage should lessen in quantity and change to a more serous composition as recovery advances. A abrupt augmentation in quantity of bloody drainage or return to frank bleeding indicates thoracic bleeding/hemothorax; abrupt cessation indicates blockage of tube, which neccesitate further essessment and management.

• Observe chest x-ray reports. Chest x-rays may direct the etiological factors of the impaired gas exchange. Take note that radiographic studies of lung water delay behind clinical presentation by twenty-four hours.

• Utilize pulse oximeter to examine oxygen saturation and pulse rate. Pulse oximeter is a valuable tool to notice alteration in oxygenation. Oxygen saturation ought to be sustained at 90% or greater. This tool can be particularly useful in the outpatient or rehabilitation location where patients at risk for desaturation from chronic pulmonary diseases can examine the effects of exercise or activity on their oxygen saturation levels. Home oxygen therapy can then be ordered as necessary. Patients should be examined for necessitate of oxygen both at rest and with activity. An elevated liter flow of oxygen is usually necessary for activity versus rest.

• Watch ABGs and observe changes. Elevating PaCO2 and diminishing PaO2 are manifestations of respiratory failure. As the patient starts to fail, the respiratory rate will fall and PaCO2 will start to increase. A number of patients, such as those with COPD, have a major reduction in pulmonary reserves, and any physiological stress may lead to acute respiratory failure.

·         Watch out for utilization of accessory muscles and/or pursed-lip breathing. Elevated work of breathing and cyanosis may signify augmenting oxygen consumption and energy expenditures and/or diminised respiratory reserve.

Therapeutic Interventions (Tx)

·         Give supplemental oxygen using nasal cannula, partial rebreathing mask, or high-humidity face mask, as ordered attempting to keep oxygen saturation at 90% or greater. Makes the most of available oxygen, particularly while ventilation is lessen because of anesthetic, depression, or pain, and during phase of compensatory physiological shift of circulation to residual functional alveolar units.

• Prevent high concentration of oxygen in patients with COPD. Hypoxia triggers the drive to breathe in the chronic CO2 retainer patient. When administering oxygen, close observation is very important to avoid dangerous augmentation in the patient’s PaO2, which could result in apnea.

NOTE: If the patient is permitted to eat, oxygen still should be given to the patient however in a different method, such as, changing from mask to a nasal cannula. Eating is an activity and additional oxygen will be needed than when the patient is at rest. Instantaneously after the meal, the prior oxygen delivery system must be returned.

• Adjust patient’s position every 2 hours. This promotes mobilization of secretions and drainage.

• Align patient to promote ventilation/perfusion matching. Make use of upright, high-Fowler’s position whenever feasible. High-Fowler’s position permits for maximum diaphragm excursion. When patient is aligned on side, the good side should be at the base.

• Align with correct body position for maximum respiratory excursion, if tolerated, head of bed at 45 degrees. This allows optimal lung expansion; enhance air exchange and mobilization of secretions.

·         Assist with chest physiotherapy (e.g., postural drainage and percussion of nonaffected area, blow bottles/incentive spirometer). Facilitates deeper respiratory effort and promotes drainage of secretions from lung segments into bronchi, where they may more readily be removed by coughing/suctioning. Aids in clearing secretions, which improves ventilation, allowing excess CO₂ to be eliminated

• Give extension tubing or portable oxygen apparatus for patients who should be ambulatory. These uphold activity and aids more efficient ventilation.

• Help with splinting the chest for postoperative patients. Splinting maximizes deep breathing and coughing efforts.

·         Keep patency of chest drainage system for lobectomy, segmental or wedge resection patient. Drains fluid from pleural cavity to uphold re-expansion of residual lung parts.

·         Prevent aligning patient with a pneumonectomy on the operative side; as a substitute, favor the “good lung down” position. Research reveals that aligning patients following lung surgery with their “good lung down” optimizes oxygenation by utilizing gravity to improve blood flow to the healthy lung, therefore producing the greatest possible match between ventilation and perfusion.

·         Raise head of bed as patient needed or tolerated. Enhances optimal chest expansion, making it easier to breathe and improving physiological or psychological comfort.

• Regularly check the patient’s alignment so that he or she does not slip down in bed. This would make the abdomen to compress the diaphragm, which would lead to respiratory embarrassment.

• Suction as necessary. Suction clears secretions if the patient is not capable of effectively clearing the airway. Airway obstruction blocks ventilation that impairs gas exchange.

• To avoid fatigue, pace activities and schedule rest periods. Even simple actions such as bathing during bed rest can result to fatigue and escalate oxygen consumption.

• Give reassurance and alleviate anxiety:

1)     Include an agreed-on technique for the patient to call for assistance, such as call light or bell.

2)     Keep on with the patient during periods of respiratory distress.

• Foresee necessitate for intubation and mechanical ventilation if patient is incapable to sustain adequate gas exchange. Prompt intubation and mechanical ventilation are suggested to avoid full decompensation of the patient. Mechanical ventilation offers supportive care to sustain sufficient oxygenation and ventilation to the patient. Management also requires concentrating on the underlying root factor that leads to respiratory failure.

• Give medications as ordered. The type of medication depends on the root factors of the problem. For example, antibiotics for pneumonia, bronchodilators for COPD, anticoagulants/thrombolytics for pulmonary embolus, and analgesics for thoracic pain.

·         Help with classification/management of underlying cause. management of disorder is aimed at at enhancing alveolar ventilation. Addressing the primary situation upholds correction of the acid-base disorder.

·         Offer concise clarifications of what is happening and anticipated effects of interventions. Alleviates anxiety due to unknown and may assist lessen fears concerning personal safety.

Educative (Edx)

• Educate the patient proper deep breathing and coughing techniques. These make possible sufficient air exchange and mobilization of secretion.

• Give details about necessitate to limit and schedule activities to reduce oxygen consumption during the acute periods. Persuade rest periods or restrict activities to patient tolerance. Elevated oxygen consumption/need can lead to augmented dyspnea and alteration in vital signs with activity; but, early ambulation is preferred to help out avoid pulmonary complications and to get and sustain respiratory and circulatory effectiveness. Sufficient rest balanced with activity can avoid respiratory compromise

• Give explanation about the type of oxygen therapy being utilizedd and why its continuance is significant. Issues in relation with home oxygen use, storage, or precautions require to be addressed.

• Help patient in getting home nebulizer, as proper, and coach in its utilization in collaboration with respiratory therapist.

• Persuade deep breathing, utilizing incentive spirometer as ordered. This avoids/decreases atelectasis and enhances re-expansion of small airways.

·         Persuade expression of worries or feelings. Respond to questions honestly. Visit regularly, organize for significant other or visitors to stay with patient as indicated. Anxiety is a symptom of psychological distressess and physiological reactions to hypoxia. Offering reassurance and improving sense of security can lessen the psychological component, thus lessening oxygen demand and adverse physiological reactions.

• Persuade or help with ambulation as neccessary. This enhances lung expansion, mobilizes secretions, and facilitates deep breathing

• Persuade patient to breathe gradually and deeply. Talk in a low, calm tone of voice; give safe milieu. May help out reassure and pacify the troubled patient, thus facilitating the lessening of respiratory rate. Aids patient to reclaim control.

• Persuade or help with deep-breathing exercises and pursed-lip breathing as fitting. Enhances optimal ventilation and oxygenation and lessens/avoids atelectasis.